Poor Evidence and Erroneous Conclusions

 

The following letter is part of a lengthy correspondence that the author conducted with a paleontologist. More of the correspondence will be posted at a later time.

Erroneous Conclusions

By Israel Zwick

February 7, 2006

Dear XXXXX:

I’m not quite finished reading Stephen Jay Gould’s 1300-page magnum opus that was published posthumously, but so far I still see the same problems as in the literature that you gave me from Jennifer Clack and Kevin Padian. That is, none of these authors are providing an adequate genetic mechanism to account for the gross morphological changes needed for macroevolution to occur. First they make an a priori assumption that there was significant genetic variation, then they use a posteriori knowledge and reasoning to suggest evolutionary sequences. Gould even acknowledged this on page 684, where he wrote, “For this book, despite its exuberant length, largely restricts itself to the Darwinian tradition of conventional causal explanations based on selection as a central mechanism.” First he assumes that there is sufficient genetic variation, then natural selection will do the rest, and the fossils will tell the whole story. His brief discussion of “evo-devo” and Hox genes is no longer relevant because Derrick Rancourt at the University of Calgary has already demonstrated that mutations in vertebrate Hox genes will result in individuals that are dysmorphic and dysfunctional, not more adaptive. So far there is no evidence that the redundancy of the Hox complex will permit sufficient flexibility for macroevolution of the body plan. Kevin Padian also recognized this difficulty in his review of Gould’s book. Padian observed, “Selection does not place those combinations in organisms, it only selects them once they are there. So it is important to separate the question of where variations come from and the question of what happens to them in populations once they appear.” On his website, Padian noted, “One of the most pressing evolutionary problems is how new major adaptations (which often “define” major evolutionary groups) get started.”

It is widely believed that genetic mutation is the causal agent for macroevolutionary changes to occur. However, David Buchanan at Oklahama State University, notes in his book and course on Animal Breeding:

Mutations occur spontaneously as changes in the base sequence of DNA molecules. They are nearly always deleterious since any random change in the base sequence is very unlikely to make a change that is desirable. They are not often of much concern to livestock producers since the changes they cause in livestock herds are quite small. This is a result of their infrequent occurrence and the fact that they often result in the death of the organism, or at least impaired function, if they express themselves. Since the death will, in many cases, occur early in pregnancy the owner will never know anything is wrong except that the female did not retain her pregnancy. It should be remembered however, that mutations are the only manner by which new genes are generated. While usually deleterious, such things as the polled condition in several breeds of cattle are also the result of mutations that occurred sometime in the past.

In the absence of a genetic mechanism for macroevolution, it is necessary to reexamine the theory and consider alternative hypotheses. To illustrate, I would like to provide an analogy:

Policemen enter a house in response to a report of gunshots. They see a corpse lying on the ground with four bullet holes. Nearby, a man is sitting on a chair with a smoking gun in his lap. There are four bullets missing from the cartridge. The empty shells near the corpse match the bullets for the gun. The conclusion is obvious. The police move to arrest the man sitting in the chair. As they do so, they discover that the man is a quadriplegic. There is no way that he could have fired the gun and shot the victim. So the police develop an alternative hypothesis. Someone came into the house, shot the victim, put the gun into the lap of the quadriplegic, then escaped through the back door.

The same situation applies to macroevolution. Yes, it’s true that the data from fossils, homologies, and DNA analysis is strongly suggestive of common ancestry and an evolutionary process. But if there is no adequate mechanism for it to occur, then it is necessary to develop an alternative hypothesis. Yes, we know that genetic variation can give rise to hundreds of varieties of ducks, geese, and chickens. Poultry breeders are coming up with new varieties all the time. But with all the billions of chickens that are being grown, they are still basically chickens. No one has yet reported a flying chicken, or any other major morphological variations. I know that you are going to say that evolution is a process that takes millions of years. But if the high-tech selective breeding that we have in today’s poultry industry, hasn’t produced any radical changes with billions of animals, then why would you believe that theropods mating in the wild would eventually result in chickens and hawks? It takes much more than wings and feathers to produce a duck, swan, or eagle. There are enormous differences in anatomy and physiology throughout the organism. Similarly, there are numerous morphological changes required for an aquatic animal to evolve into a terrestrial animal, or an oviparous animal to evolve into a viviparous animal. To date, there is no genetic mechanism that can account for such radical changes in body plan that would produce a new pattern of bones, muscles, blood vessels, and nerves that would function in an integrated and coordinated manner. Experimental attempts to modify the body plan during development have only resulted in dysmorphic and dysfunctional characteristics that threaten the survival of the organism, not enhance its viability. So if it looks like a duck, and walks like a duck, and talks like a duck, then it descended from a duck, or something very similar. It’s impossible to develop novel structures without major changes in the entire organism. To illustrate, I would like to offer another analogy:

Kingdom: Motor Vehicles

Phylum: Ford Motor Cars

Class: Passenger cars

Order: Four-door sedans

Family: Full-size models

Genus: Crownvictoria

Species: private-use

The New York Police Department is interested in ordering new police cars and has a meeting with the Vice President of Ford Marketing. Below is the discussion that ensues:

NYPD: We would like to order 100 new vehicles for our department but they have to be modified to meet our requirements.

FORD: What do you need?

NYPD: Well our vehicles are used for 20 hours per day and often have to maneuver through traffic at high speeds.

FORD: We can give you a Crown Victoria with a heavy-duty, 8-cylinder engine.

NYPD: Our officers sometimes travel at 90 mph.

FORD: We can give you heavy-duty breaks and steering.

NYPD: Our officers sit in the car for long periods so we want them to be comfortable.

FORD: We can give you ergonomic front seats and climate control.

NYPD: We would like our cars to plow through snow so they can respond to emergencies during a snowstorm.

FORD: We’re sorry, we can’t mount a snowplow on a Crown Victoria, you would have to get a Ford SUV if you want a snow-plow and four-wheel drive.

NYPD: Never mind the plow, we’ll stick with the Crown Victoria.

So now we have a new species of car: Crownvictoria policecar. After the NYPD engineer leaves, the president of the Yellow Cab Co. comes in.

YELLOW: We would like to order 100 new vehicles for our taxi fleet but they have to be modified to meet our requirements.

FORD: What do you need?

YELLOW: Our vehicles are used for 20 hours per day in heavy NYC traffic.

FORD: We can give you a Crown Victoria with a heavy-duty package that includes the engine, air conditioning, brakes, and cooling system.

YELLOW: We want the passenger seat to be durable.

FORD: We can give you thick vinyl or leather for the passenger seat.

YELLOW: We would like our passengers to be comfortable

FORD: We can give you climate controls and satellite radio for the rear compartment.

YELLOW: We would like to have an assistive device that will enable us to pick up passengers from medical facilities.

FORD: We’re sorry, we can’t mount a hydraulic lift on a Crown Victoria. You would have to get a Ford Van if you want that.

YELLOW: Never mind, we’ll stick with the Crown Victoria.

So now we have another new species of car: Crownvictoria taxicab.

Similarly, genetic variation has its limitations. Variations from genetic recombinations can make an organism a little bigger, stronger, faster, smarter, or more fertile to adapt to new environmental demands, but cannot result in novel structures or major changes in body plan. Any major modification of an organ would require concomitant modifications in the associated skeletal, muscular, vascular, and neural structures. So for an eye, a uterus, or a wing to develop increased complexity, there would have to be concomitant changes in the supportive skeletal, muscular, and vascular structures. Most important, there have to be gross changes in the nervous system to develop the neural integration needed to get the whole thing to work in a coordinated fashion. Otherwise, the new variations would more likely be maladaptive and lead to extinction. Neither gradual anagenesis, cladogenesis, nor punctuated equilibrium, can account for the gross morphological changes that are necessary for macroevolution to occur. As Padian correctly observed, natural selection can’t operate if there is no source for the variations. It can only choose the variations, not produce them.

Major variations don’t come easily. In his book on Animal Breeding, David Buchanan reports on new technologies that are being used today to improve livestock:

In recent years, several new and exciting technologies have emerged in the fields of reproductive physiology and molecular biology that may allow increased improvement of livestock through animal breeding. These technologies can be separated into two main categories: embryo manipulations and DNA manipulations. Embryo manipulations would include such techniques as cryopreservation of gametes and embryos, artificial insemination, in vitro fertilization, multiple ovulation and embryo transfer, and even cloning, the production of multiple copies of identical individuals. DNA manipulations would include such techniques as gene marker assisted selection and the production of genetically engineered, or transgenic, livestock.

Recall that improvement of livestock as a result of genetic selection is determined by several factors, including the heritability of a trait, the amount of variation among potential replacements, the genetic superiority of the selected replacements, and the time interval required to turn over a generation. These concepts were summarized in the formula:

R per year = h2 x S/L

where

R is the response
h2
is the heritability
S is the selection differential
L is the generation interval.

It follows then that for any new technology to be of use in enhancing annual genetic improvement, it would have to either increase the heritability of a trait (or the accuracy with which we can identify the most genetically superior animals), increase the selection differential (or the measured superiority of selected replacements), or decrease the generation interval. In this chapter we will briefly describe the methodologies of several embryo and DNA manipulations, and discuss the potential of each technique for contributing towards increased genetic improvement of livestock.

All this sophisticated science and technology can do no more than effect minor improvements in livestock. It will not create any radically new species. If this is so, then how can you believe that therapods mating in the wild could eventually give rise to flying birds, even after millions of years. If the changes can’t occur, then they won’t occur even after millions of years. So allopatric speciation may result in new varieties of lizards and birds but won’t result in lizards developing from fish or birds developing from therapods. There just isn’t a genetic mechanism for this to happen.

Have I made any erroneous assumptions or conclusions here? If I have, please correct me so that I can get a better understanding of evolutionary processes. If my conclusions are correct, then you would have to agree that the validity of the theory of macroevolution needs to be carefully reexamined by the scientific community. If there is no mechanism to produce morphological novelties and radical changes in body plans, then alternative hypotheses need to be considered. If there are no alternative hypotheses available, then it would be preferable for the scientific community to say, “We don’t know how the complexity and diversity of life on earth came about.” The lack of an alternative hypothesis is not a sufficient reason to cling tenaciously to a flawed hypothesis. I would prefer to hear, “We don’t know” from the scientific community than to continue reading lengthy, prolix, and esoteric books about a theory that is deficient in empirical support.

I look forward to receiving your response.

Respectfully,

Israel Zwick

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